I changed it to 9999, restarted the Sip server tried to make several calls but still it doesn't work.

Please advice what else could be done?

This is the Session Details when I make a call from user 160 to user 110. EX-SID 84 From-uri sip:160@196.219.160.162 [behind NAT] From-ip 196.219.160.225:65119 (UDP) From-if 196.219.160.162:5060 To-uri sip:110@196.219.160.162:5060 [behind NAT] To-ip 196.219.160.225:49264 (UDP) To-if 196.219.160.162 ...

Yes the handytones and the x-lite are registered at the sip server, also when I make a call from one hanytone to another I see at the log that user 110 is inviting user 160, but I never hear a ring on the other side.

There is no dial plan, I don't know what the dial plan does?

1. Brekeke Product Name and version: Sip Server Version 2.4.3.9 Evaluation 2. Java version: ver 6 3. OS type and the version: Windows server 2003 4. UA (phone), gateway or other hardware/software involved: X-Lite, Grandstream 286 5. Select your network pattern from http://www.brekeke-sip.com/bbs ...